. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Figure 4. Diagrams of the surgical operations involved in isolating hlastomeres from the 8-cell stage (A). Isolation of animal and vegetal quartets (B) and quarter-embryos (C). The endodermal territories as mapped hy Ortolani (1954) are indicated by diagonal lines. Size and pattern of the cells can be learned initially from Conklin'sf 1905 (diagrams, which are exceptionally accurate. One can also observe the shapes, sizes, and po- sitions of cells (//; situ) when isolated half-embryos divide again in culture. Partial larvae
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. Figure 4. Diagrams of the surgical operations involved in isolating hlastomeres from the 8-cell stage (A). Isolation of animal and vegetal quartets (B) and quarter-embryos (C). The endodermal territories as mapped hy Ortolani (1954) are indicated by diagonal lines. Size and pattern of the cells can be learned initially from Conklin'sf 1905 (diagrams, which are exceptionally accurate. One can also observe the shapes, sizes, and po- sitions of cells (//; situ) when isolated half-embryos divide again in culture. Partial larvae resulting from given blas- tomere pairs have very distinctive morphologic features. Figures 5-9. dona intestinalis embryo and isolated blastomeres photographed after brief fixation in the Karnovsky (1965) fixative. Fig- ure 5: 8-cell stage in lateral view as in Figure 4A. Figure 6: Animal quartet of cells from 8-cell stage. Figure 7: Vegetal quartet of cells from the 8-cell stage. Figure 8: Isolated cell pair after the next division. Figure 9: Isolated cell pair after the next division. The embryo orientation letters are AN (animal), VEG (vegetal), A (anterior), and P (posterior). All magnifications are the same; bar in Figure 7 = 50f<m. by which the accuracy of one's initial selection is easily confirmed. A Ikalinc phosphatase development in partial embryos Only partial embryos originating from blastomeres known to contain endodermal lineages (Fig. 1) devel- oped groups of cells containing alkaline phosphatase in the resulting partial larvae (Table I). In larvae developing from dechorionated whole embryos, there was always enzyme staining in the endodermal mass of the head re- gion (Figs. 3, 10). Normal specimens were included as positive controls in each of the various enzyme incuba- tions (Gomori method) with partial embryos. Some lar- vae show staining in the endodermal strand along the tail and in the few notochordal cells at the tip of the tail; both are evid
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
